Method and apparatus for increasing therapy compliance

ABSTRACT

A breathing assistance unit for providing pressurized heated humidified air at to a user is configured to increase user compliance. The breathing assistance unit has means for generating positive emotional and cognitive states of a user about the therapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. patent application Ser. No. 12/513,752, filed on Oct. 14, 2009, which claims priority under 35 U.S.C. §371 of PCT Application No. PCT/NZ2007/00328, filed on Oct. 31, 2007, which claims the priority benefit of New Zealand Application No. 560235, filed on Jul. 30, 2007 and U.S. Provisional Application No. 60/864,501, filed on Nov. 6, 2006, each of which is hereby incorporated by reference in its entirety.

This application hereby incorporates by reference the entirety of the following applications: (1) U.S. Provisional Patent Application No. 61/084,322, which was filed on Jul. 29, 2008; (2) U.S. Provisional Patent Application No. 61/173,656, which was filed on Apr. 29, 2009; (3) U.S. Provisional Patent Application No. 61/184,379, which was filed on Jun. 5, 2009; (4) U.S. Provisional Patent Application No. 61/250,186, which was filed on Oct. 9, 2009; (5) U.S. Provisional Patent Application No. 61/267,270, which was filed on Dec. 7, 2009; (6) PCT/NZ2009/000151, which was filed on Jul. 29, 2009; (7) PCT/NZ2010/000083, which was filed on Apr. 29, 2010; (8) PCT/NZ2010/000103, which was filed on Jun. 3, 2010; (9) PCT/NZ2010/000201, which was filed on Oct. 8, 2010; and (10) U.S. Design Pat. application No. 29/334652, which was filed on Oct. 1, 2009;

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to methods and apparatus for sensing a condition of a body of a living thing receiving a respiratory gas. More particularly, the present invention relates to methods and apparatus for improving patient compliance in continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) treatment. Compliance, as used in the CPAP field, can mean the duration of nightly use of the device, or the amount of time that the device is switched on and being worn.

2. Description of the Related Art

Obstructive sleep apnea (OSA) is a common sleep breathing disorder affecting approximately 2-4% of the middle-aged population. Continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) are two treatments for OSA. While CPAP and BiPAP provide an effective treatment of OSA, compliance is often low.

SUMMARY OF THE INVENTION

Applicants have discovered that an often overlooked influence on CPAP compliance is the psychological aspect of devices. People who have a more positive impression of CPAP therapy are believed to be more likely to adhere to and comply with treatment. This includes people who are more likely to understand the risks associated with OSA and the benefit of CPAP and people who describe a positive belief in their ability to use the CPAP.

Thus, the user-friendliness of a device may be important in improving compliance. Similarly, a device that is aesthetically pleasing may promote interaction and reduce cognitive dissonance as a barrier to therapy. This interaction between the aesthetics and the objective elements of treatment has been described in the dual process model of Leventhal H et al., The impact of communications on the self-regulation of health beliefs, decisions, and behavior, Health Education Behavior 1983; 10(1): 3-29. The theory states that the quality (emotional elements such as aesthetics) and clarity (cognitive elements such as ease of use) of a medical message, such as in the interaction with a medical device, can determine a patient's adherence.

Historically, to improve compliance, CPAP designers and manufacturers have focused on technological improvements, such as pressure modification and humidification. However, there is limited evidence that these technology-centric advances have any impact on compliance. Instead, improved user perception of treatment may lead to improved compliance with that treatment. It is believed that, through making the device more aesthetically pleasing and easy to use, the patient is more likely to comply with treatment.

Thus, a device has been designed to include means for improving the user-friendly nature of the device while also improving the aesthetics of the device.

In some configurations, a positive airway pressure device is configured to improve patient compliance by providing an improved user-friendliness and by reducing cognitive dissonance as a barrier to therapy. The positive airway pressure device comprises a housing comprising an outer surface. The outer surface comprises a front wall, a rear wall, a first side wall extending between the front wall and the rear wall and a second side wall extending between the front wall and the rear wall. The front wall is slightly inclined such that an upper portion of the front wall is closer to the rear wall than a lower portion of the front wall. The front wall is connected to each of the first side wall and the second side wall with a rounded corner. A top wall is connected to each of the front wall, the first side wall, the second side wall and the rear wall. A control knob and a control display are positioned on the front wall with the control display being positioned directly above the control knob. The control display comprises a clock display and a smiley face shaped indicator. A blower unit is disposed within the housing. An inlet to the blower unit is fluidly connected to ambient air and extends through at least one of the front wall, the first side wall, the second side wall and the rear wall. A humidification compartment is disposed within the housing. An upper portion of the humidification compartment is covered by a removable lid. The lid is removably attached to the housing and defines a handhold location for carrying of the positive airway pressure device. The humidification compartment is adapted to receive a humidifier chamber. The humidifier chamber is an open top container with a heat-conducting surface. An airflow outlet extends from one of the front wall, the first side wall, the second side wall and the rear wall. The airflow outlet is pivotable or rotatable relative to the housing and the airflow outlet is connected to one of the humidification chamber and one of the front wall, the first side wall, the second side wall and the rear wall. An internal power supply is positioned within the housing.

In some configurations, a positive airway pressure device is configured to improve patient compliance by providing an improved user-friendliness and by reducing cognitive dissonance as a barrier to therapy. The positive airway pressure device comprises a housing comprising an outer surface. The outer surface comprises a front surface, a first side surface and a second side surface extending rearward from the front surface. A smooth contour is formed by the front surface, the first side surface and the second side surface. A control knob and a control display are positioned on the front wall. The control display comprises a clock display and a smiley face shaped indicator. A blower unit is disposed within the housing with an inlet to the blower unit being fluidly connected to ambient air and extending through at least one of the front wall, the first side wall, and the second side wall. A humidification compartment also is disposed within the housing. An internal power supply is positioned within the housing.

In some configurations, a method of improving patient compliance with a program of positive airway pressure therapy comprises providing a positive airway pressure device that comprises means for generating positive emotional and cognitive states of a user with respect to the therapy.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The term ‘comprising’ as used m this specification means ‘consisting at least in part of, that is to say when interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present.

It is an object of the present invention to provide a breathing assistance apparatus which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of a preferred embodiment, which embodiment is intended to illustrate and not to limit the invention, and in which figures:

FIG. 1 shows a schematic view of a user receiving humidified air from a modular blower/humidifier system of a known, prior art, type.

FIG. 2 shows a schematic view of a user receiving humidified air from an integrated blower/humidifier system of a known, prior art, type.

FIG. 3 shows a perspective view of the preferred embodiment of the integrated blower/humidifier of the present invention, which has a separate humidifier chamber and assisted breathing unit that are shown with the humidifier chamber in place within the blower unit ready for use.

FIG. 4 shows a perspective view of the blower unit of FIG. 3, with the humidifier unit removed (not shown).

FIG. 5 a shows a rear view of the blower unit of FIG. 3, with a section line D-D shown.

FIG. 5 b shows a cross-sectional view along section line D-D of the blower unit of FIG. 4.

FIG. 6 shows an exploded view of the blower unit and the humidifier unit of FIG. 3.

FIG. 7 shows a schematic detail view along section line DD of the internal structure of the blower unit.

FIG. 8 shows a cutaway view of the blower unit from underneath and to the rear looking forwards, with detail of an air inlet duct, a power supply and power supply sub-housing, a fan, and an air path through the unit shown.

FIG. 9 shows a cutaway view of the blower unit from underneath and to the rear looking forwards, with the rearmost part of the blower unit cut away to show detail of the air path around the power supply sub-housing.

FIGS. 10 a and 10 b show cutaway views of the blower unit from underneath and to the rear looking forwards, with FIG. 10 a showing the blower unit with the base and part of the rear wall removed, and FIG. 10 b showing the rear part of the blower cutaway further forward than the view of FIG. 10 a, to show detail of the air path over the power supply sub-housing.

FIG. 11 a shows a cutaway bottom view of the blower unit of the preceding Figures, with the base removed.

FIG. 11 b shows a schematic view of the blower of FIG. 11 a, with the air path and turbulence shown as the air passes firstly into the air inlet duct, then over and around the power supply sub-housing, and then into and out of the fan.

FIG. 12 shows a schematic line view of the blower unit underneath and to the rear looking forwards, with the air path and turbulence shown as the air passes firstly into the air inlet duct, then over and around the power supply sub-housing, and then into and out of the fan.

FIG. 13 a shows a rear view of the humidifier chamber of the present invention, with a humidifier chamber lid and a locking handle shown in exploded view above the humidifier chamber, and a section line A-A shown.

FIG. 13 b shows a cross sectional view along the line A-A of the humidifier chamber, humidifier chamber lid and locking handle of FIG. 13 a.

FIG. 14 shows a schematic cross-section of part of the front of the blower unit.

FIG. 15 shows a preferred form of main menu that is displayed on a display panel of the integrated blower/humidifier of FIG. 3.

FIG. 16 shows a schematic view of the internal structure of the preferred form of fan and motor that can be used in the blower unit of FIG. 5 b.

FIG. 17 shows a partial view of the lid of FIG. 6, and a locking handle used to hold the lid in position, with the lid and locking handle separated.

FIG. 18 shows a preferred form of carry case that can be used with the breathing assistance apparatus of the present invention, closed and upright resting on its end base.

FIG. 19 shows a cutaway side view of the carry case of FIG. 18, resting on its side base, ready to be opened, with an integrated breathing assistance apparatus of the type shown in FIG. 3 located in the carry case.

FIG. 20 shows a top view of the carry case of FIGS. 18 and 19, with the lid or top half not shown, and an integrated breathing assistance apparatus of the type shown in FIG. 3 located in the carry case ready for transport.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A schematic view of a user 3 a receiving air from a known (prior art) modular assisted breathing unit and humidifier system is shown in FIG. 1. Pressurized air is provided from an assisted breathing unit or blower 1 a via a conduit 41 to a humidifier chamber 2 a. Humidified, • heated and pressurized gases exit the humidifier chamber 2 a via a conduit 21, and are provided to the patient or user 3 via a user interface 4. The user interface 4 shown in FIG. 1 is a nasal mask, covering the nose of the user 3. However, it should be noted that in systems of these types, a full face mask, nasal cannula, tracheostomy fitting, or any other suitable user interface could be substituted for the nasal mask shown.

A schematic view of the user 3 receiving air from a known, prior art integrated blower/humidifier unit 5 is shown in FIG. 2. The system operates in the same manner as the modular system shown in FIG. 1, except that humidifier chamber 2 b has been integrated with the blower unit 1 b to form the integrated unit 5.

The integrated blower/humidifier unit 6 of the present invention can be substituted for the unit 5 of FIG. 2. The preferred form of the integrated blower/humidifier unit 6 is shown assembled and ready for use in FIG. 3. The unit 6 has two main parts: An integrated assisted breathing unit 7 (also known as a blower unit), having an outer shell which forms part of the breathing unit 7 and also encloses the working parts of the assisted breathing unit—e.g. the fan, internal-ducting and the internal control system; and a humidification unit 31 (described in detail below).

Assisted Breathing Unit

The preferred form of assisted breathing unit or integrated unit 6 will now be described with reference to FIGS. 4-17.

The integrated unit 6 consists of two main parts: an assisted breathing or blower unit 7 and a humidification unit 31. The humidification unit 31 is enclosed within the external casing of the integrated unit 6 in use, except for the top part. The structure of the humidification unit 31 is described in detail below.

The blower unit 7 has an outer shell that is a generally rectangular block with substantially vertical side and rear walls, and a front face that is angled slightly rearwards. In the preferred embodiment, the walls, base and top surface are all manufactured and connected as far as possible to minimize the occurrence of seams, and any necessary seams are sealed. In some embodiments, the housing or outer shell comprises the front wall, the side walls and the rear wall. The housing also can include a top wall or upper wall. At least the front wall and the side walls preferably are connected by rounded corners to provide a more aesthetically pleasing appearance. These features are clearly shown in FIGS. 3, 4 and 8.

The illustrated housing has a dramatically reduced footprint. In some embodiments, the footprint is less than about 200 mm by about 200 mm. Preferably, the footprint is about 190 mm deep by about 170 mm wide. Given a typical bedside table with a width of about 480 mm and a depth of about 480 mm, the footprint occupies less than about 20% or, more preferably, less than about 15% of the typical table top area. Preferably, the footprint is less than about 40000 mm². More preferably, the footprint is less than about 35000 mm². Even more preferably, the footprint is less than about 32300 mm². The housing also preferably is less than about 300 mm high, more preferably less than about 200 mm high and even more preferably less than about 160 mm high. The volume of the housing preferably is less than about 0.008 m³. More preferably, the volume of the housing is less than about 0.006 m³.

This outer shell encloses the working parts of the blower unit 7, and forms part of the blower unit 7. As shown in FIG. 4, a control knob 8 is located on the lower section of the front face of the integrated unit 6, with a control display 9 located directly above the knob 8. A patient outlet 25 is shown passing out of the rear wall of the integrated unit 6. In the preferred embodiment, in use the free end of the outlet 25 faces upwards for ease of connection. However, the preferred form of patient outlet 25 can be rotated to one side or the other to move or align it in a more convenient position for storage or for a more convenient use position. The patient outlet 25 is adapted to allow both pneumatic and electrical connection to one end of a conduit—e.g. conduit 21—running between the unit 6 and a patient interface—e.g. interface 4. An example of the type of connector that can be used and the type of dual connection that can be made is described in U.S. Pat. No. 6,953,354. It should be noted that for the purposes of reading this specification, the patient interface can be thought of as including both the interface 4 and the conduit 21 where it would be appropriate to read it in this manner.

In FIG. 3, a locking handle 22 is shown in position on the top surface of the integrated unit 6. The locking handle 22 is a separate item that can be unlocked and removed from the remainder of the integrated unit 6. The locking handle 22 includes a grip 30, adapted to act as a handle to allow a user to lift and carry the integrated unit 6, and also adapted to enable the handle 22 to be rotated from a locked position to an unlocked position. The locking handle 22 can be releasably locked to the remainder of the integrated unit 6. The function of the locking handle 22 will be more fully described below in the ‘humidifier unit’ section.

FIG. 4 shows the integrated unit 6 with the locking handle 22 removed and the humidification unit 31 not shown. That is, just the blower unit 7 is shown. The top surface of the blower unit 7 includes a circular humidifier aperture 1000, leading to an internal humidifier compartment 11. The opening includes a rim 24 located around the circumference of the opening. In use, a humidifier chamber 12 is located within the compartment 11. The humidifier chamber 12 will be described in detail below. The humidifier chamber 12 is in use fully enclosed inside the compartment 11, except for the uppermost part. When the chamber 12 is described as enclosed in the blower unit 7, it can be taken to mean fully enclosed except for the uppermost portion, as well as fully enclosed including the uppermost portion.

The internal structure of the blower unit 7 will now be described with reference to FIGS. 4 and 5. A heater base 23 is located at the bottom of the compartment 11. The heater base 23 is mounted to the floor of the compartment 11 in such a way that it has a small amount of elastic or compression resilience. That is, it can be pushed downwards a short distance within the compartment, but will push back against any downwards force that is applied. In the absence of any downwards force it will return to its initial position. This can be achieved by spring loading the base 23, or by any other of the methods that are known in the associated arts. A blower inlet port 13 and blower outlet port 14 are located on the wall of the compartment 11, towards the top of the compartment 11. A replaceable filter can be provided at the inlet port 13. Preferably, the filter is replaceable from outside of the outer shell or housing of the blower unit.

In the preferred embodiment, the blower ports 13, 14 are aligned so as to mate with humidifier ports 15, 16 located on the humidifier chamber 12 in use (described in detail below) so as to form a blower-to-humidifier gases route that allows gases to exit the blower 7 and enter the humidifier chamber 12. It should be noted that other forms of blower inlet are possible. For example, a conduit running between the blower unit 7 and e.g. the lid of the humidifier chamber 12.

As shown in FIGS. 7 and 8, the integrated unit 6 includes an inlet vent 101 to draw air in from atmosphere. The integrated unit 6 also includes a mechanism for providing a pressurized air flow from the inlet vent 101 to the humidifier chamber. This vent 101 can be located wherever is convenient on the external surface of the integrated unit 6. In the preferred embodiment, as shown in FIG. 8, it is located on the rear face of the blower unit 7. In the preferred embodiment, air is drawn in through the vent 101 by a fan unit 100 that acts as the preferred form of pressured air flow mechanism (described in detail below). The air is ducted or otherwise directed through the casing to the inlet port 13. In use, air will exit the main body of the blower unit 7 via the inlet port 13 and then enter the humidifier chamber 12, where it is humidified and heated, before passing out of the chamber 12 through the outlet port 14, which is directly connected to the patient outlet 25. The heated humidified gas is then passed to the user 3 via e.g. a conduit 21. The patient outlet 25 is adapted to enable pneumatic attachment of the patient conduit 21, and in the preferred embodiment, electrical connection at the outlet 25 is also enabled via an electrical connector 19. A combined electrical and pneumatic connection can be useful for example if the conduit 21 is to be heated. Electrical heating of a conduit such as conduit 21 can prevent or minimize the occurrence of condensation within the conduit 21. It should also be noted that the outlet connection does not have to be via the housing of the integrated unit 6. If required, the connection for the conduit 21 could be located directly on an outlet from humidifier chamber 12. The preferred form and variations can generally be referred to as connection mechanisms.

As shown in FIGS. 6 and 7, the inlet port 13 is offset. That is, the port is positioned facing into or out of the corner of the integrated unit 6 between the side wall and the front face. In contrast, outlet port 14 is directly aligned with the rear wall of the integrated unit 6. It can also be seen from FIG. 6 that the circular compartment 11 is sized to just fit within the generally square plan view profile of the integrated unit 6. Offsetting the inlet port 13 towards the corner allows a more efficient use of the space within the assisted breathing integrated unit 6, and allows the size of the integrated blower/humidifier unit 6 to be minimized.

The locking handle 22 and the integrated unit 6 include a locking mechanism for locking the handle 22 to the integrated unit 6. In the preferred embodiment, the locking mechanism is as follows: the rim 24 includes two mating grooves 26 located just below the rim 24, spaced opposite each other on the circumference of the rim 24. More than two of the mating grooves 26 can be used if required. The grooves 26 correspond to an equal number of mating lugs 27 on the locking handle 22. The mating groove or grooves 26 have an entry point 28 on the rim 24, with the main part of the groove 26 located slightly below the rim 24. The lugs 27 are pushed downwards into the entry points 28, and the handle is rotated so that the lugs enter the main part of the grooves 26 to hold the handle 22 in place. Different locking mechanisms can be used if desired.

Humidifier Chamber with Lid

The humidifier unit 31 will now be described in more detail with particular reference to FIGS. 13 and 17.

In the preferred embodiment, the humidifier unit 31 is comprised of three main parts: humidifier chamber 12, lid 32 and locking handle 22 (counted as part of the humidifier unit for describing the operation of the integrated unit 6).

The preferred embodiment of the humidifier chamber 12 is an open-topped container, with a heat conducting base. In some configurations, the humidifier chamber 12 is desired to be dishwasher safe and can be cleaned in a standard dishwasher. The chamber 12 is sized to fit snugly within the compartment 11 on the integrated unit 6. Preferably, the chamber 12 is sized to accommodate at least about 420 ml of water. While the chamber 12 can be larger or smaller, about 420 ml has been determined to be a desirable amount of water for use in the apparatus.

The chamber 12 is enclosed within the blower unit except for the open top of the chamber 12. A fully open topped chamber 12 is the preferred form. However, an alternative form of the chamber 12 could have a closed top surface, and would include an opening on the chamber (not necessarily on the top surface), sized appropriately so that a user can easily fill the chamber 12. The preferred form of chamber 12 with an open top, and the alternative form that includes a fill opening on the top are referred to as ‘open top’, or ‘top openings’ within this specification. The open top may also be referred to as a ‘top EU aperture’. It should also be noted that when the humidifier chamber 12 is referred to as ‘enclosed’, or ‘substantially enclosed’ in relation to the integrated breathing assistance apparatus, this has the meanings defined above. The chamber 12 is generally circular, but the lower part of the rear (relative to the integrated unit 6) is flattened as shown in FIGS. 13 a and 13 b to correspond to a ledge 33 on the lower rear side of the compartment 11. This reduces the likelihood that the chamber 12 will be oriented incorrectly in use. It should be understood that other methods of achieving the same result could also be used. For example, the chamber 12 and integrated unit 6 could include complimentary grooves and slots. The chamber 12 can also include features such as a fill or level line if required. The humidifier inlet port 15 and a humidifier outlet port 16 are located in the wall of the humidifier chamber 12, towards the top of the chamber wall. These are positioned so as to align with the blower inlet and outlet ports 13 and 14 when the humidifier chamber 12 is in position, forming the blower-to-humidifier gases route as described above. It is preferred that the corresponding ports on the blower 7 and humidifier chamber 12 are shaped so as to minimize airgaps. A good seal is preferred but not required. In the preferred form, the rim or perimeter of the chamber 12 includes a chamber seal 10, formed from soft silicone or similar. When the chamber 12 is placed in position in the humidifier compartment 11, the chamber seal 10 is pressed against the wall or walls of the compartment 11, and the body of the chamber 12 and the seal 10 increase the likelihood that the chamber 12 is sealed, so that air exiting the blower through the port 13 cannot escape to atmosphere. This helps increase the likelihood that a pressurized airstream enters the humidifier chamber 12 in use. If required, a substantially unbroken ring of sealing material such as soft silicone can be added to the wall of the compartment 11 at or close to the upper rim of the chamber 12, to form a compartment seal (not shown) instead of or as well as the chamber seal 10. In alternative embodiments the ports 13, 14 are surrounded by resilient sealing gaskets such as silicone gaskets to assist in forming a seal in use. If preferred, the resilient sealing gaskets around the ports can be used as well as the compartment and/or chamber seals.

Air enters the humidifier chamber 12 through the humidifier inlet port 15, and passes along a generally horizontal entry passage 34 towards the centre of the humidifier chamber 12. Passage 34 is offset towards one of the front corners of the unit to align with the inlet port 13 as described above. The air exits the entry passage 34 through a first aperture or opening 200 in the centre of the humidifier chamber 12 aligned facing upwards (that is, in the top of the passage). The air is then directed into the main part of the chamber by a baffle 35. In cross section, the baffle 35 is T-shaped, with a vertical central portion to deflect gases entering the chamber 12, and a substantially horizontal top ‘umbrella’ portion 202, which is circular in plan view, as shown in FIGS. 6 and 13. Air is deflected by the baffle 35 as it exits the passage 34, and then enters the main part of the chamber 12 where it is heated and humidified. The heated and humidified gases then enter an exit passage 36 on the other side of the baffle 35 through a second aperture or opening 201, with the air passing through the exit passage 36 to the chamber exit port 16 and then into the breathing unit outlet port 14, and on to the user 4 as described above. It can be seen that the baffle 35 prevents air from the inlet passage 34 from directly entering the exit passage 36 before it has been heated and humidified. The passage and baffle arrangement also serves the purpose of acting as a splash baffle as well as an air baffle. Water is obstructed from entering the passages 34 and 36 if the chamber 12 is tilted while it contains water. The umbrella portion 202 of the baffle 35 acts as a shield for the passages 34, 36, vertically occluding the apertures 200, 201, so that when a user is pouring or refilling the chamber 12, the user cannot directly pour into either of the apertures 200, 201. The top surface of the passages 34, 36 also acts as a shield to prevent a user pouring water into the passages 34, 36. It is preferred that the exit and entry apertures 200, 201 in the passages 34, 36 face upwards, as this helps to prevent water or liquid in the chamber splashing into the passages 34, 36, or otherwise entering the passages 34, 36 when the chamber 12 is tilted. The passages, 34, 36 and the baffle 35 can be generally referred to as the baffle, or the baffle mechanism.

In use, the chamber 12 is positioned (in the correct orientation) within the compartment 11. The lid 32 is then placed on top of the chamber 12. The lid 32 is sized so that it will pass through the top opening of the integrated unit 6, with the lower surface of the lid 32, close to the edge, sealing onto the upper edge of the chamber 12. In the preferred embodiment, the lid 32 has an edge perimeter portion that is aligned facing downwards. This has a central recess that is filled with a silicone seal 70 or similar that is pressed onto the upwards facing edge of the chamber 12 when the lid 32 is in position. This arrangement is shown in FIG. 13. In FIG. 13, the handle 22 is also shown vertically above the lid 32 (separate from the lid 32). The lid 32 is sized to fit into the recess shown in the handle 22 (if the handle shown in FIG. 13 is pressed vertically downwards onto the lid 32). If required, the two contacting portions of the lid 32 and the chamber 12 can also be shaped to improve the seal between the two. The central part of the lid 32 is bulged upwards so that it will stand proud of the baffle 35. The lid 32 is placed in position on the chamber 12 once the chamber 12 has been filled. The locking handle 22 is then positioned above the lid 32. As has been described above, lugs 27 on the circumference of the locking handle 22 engage with complimentary grooves 26 on the rim 24. In order to engage correctly, it is necessary in the preferred embodiment for the locking handle 22 to be pressed or pushed downwards, pushing both the lid 32 and the chamber 12 downwards onto the heater plate 12. The heater plate 12 will give slightly under the downwards pressure, allowing the locking handle 22 to be rotated so that the lugs 27 engage with the grooves or slots 26. Once the downwards force is removed, the chamber 12, lid 32, and locking handle 22 will be pressed upwards by the reaction force from the heater plate 12, with the assembly held in place by the lugs 27 and slots 26. In the preferred embodiment, the slots 26 are shaped so that the locking handle 22 cannot be rotated to disengage the lugs 27 without pressing the locking handle 22 downwards slightly first.

The locking handle 22 also includes the grip 30, which in the preferred embodiment is an arched member passing from one side of the handle 22 to the other, sized and shaped so that a user can pass at least some of their fingers underneath, so as to manipulate the locking handle 22 and to carry the integrated unit 6 if necessary. In the preferred embodiment, the locking handle 22 and the lid 32 are separate items, as described. If the handle 22 is used without the lid 32, the chamber will not be sealed, and the heated, humidified air will escape or vent to atmosphere before entering the exit port 14. Any air that does enter the port 14 will be at a lower pressure than required, due to the leaking. To increase the likelihood of correct operation, the lid can be used to seal the chamber in the preferred embodiment. This will reduce the likelihood that the unit is used incorrectly. For example, if a user fills the compartment 11 directly without using the chamber 12, or if a user forgets to place the lid 32 in position.

In the preferred form, the top portion of the lid 32 fits into a central recess in the handle 22, as can best be seen in FIG. 6 b. The lid 32 and the handle 22 are sized so that the lid 22 will snap-fit and be held in place in the handle 22 to form an integrated lid unit. The lid 22 can be disengaged from the handle 32 by pressing on its top surface or similar. However, it is preferred that the snap-fit will keep them engaged in normal usage. As the handle recess and the lid 22 are circular, they can easily rotate relative to one another when engaged. When the handle 22 is rotated to disengage it from the integrated unit 6, it will rotate easily relative to the lid 32 (which will not rotate easily due to the seal on the perimeter edge). When the handle 22 has been disengaged from the integrated unit 6, it can be lifted away from the integrated unit 6 to remove both the handle 22 and the lid 32.

It should be noted that although a round chamber 12, lid 32 and a locking mechanism (lugs 27 and slots 26) have been described, and locking/unlocking of the lid 32 is achieved by rotating the separate locking handle 22, this is not the only way in which this effect can be achieved. If a different locking mechanism is used in place of the lugs 27 and grooves 26, chambers with different profiles can be used in place of the round chamber 12 described above. For example, spring loaded clips could be used, with the clips released by a button placed in a convenient location, such as on a handle or on the outer surface of the integrated unit 6. A hinged lid could also be used, with a clip and complimentary catch located on the lid and the blower unit, to hold the lid closed in use. Alternatively or as well as, the chamber lid 32 and the locking handle 22 could be integrated as a single unit. This single unit could either be separable from the integrated unit 6 or the humidifier unit 31, or an integral part of it, for example a hinged lid similar to that suggested above. The intention of the lid 32 and handle 22 in the arrangement described above is that a user can easily remove the lid 32 in order to access the chamber 12 for refilling or similar, and that a user can then easily replace the lid 32 and handle 22 to hold the lid 32 and the chamber 12 in position inside the assisted breathing integrated unit 6.

It should be noted that as outlined above, use of a round chamber 12, with a generally square profile integrated unit 6 allows an efficient use of space so that the overall size of the integrated unit 6 can be minimized. This should be considered if using an alternative layout or locking mechanism.

Control Knob

The preferred form of construction of the control knob assembly including operable control knob 8, and attachment to the integrated unit 6 will now be described with particular reference to FIG. 14. The knob 8 is manipulable by a user to change the settings of the integrated unit. This is achieved by twisting and pushing the knob 8 to generate control signals.

In the preferred embodiment, the integrated unit 6 includes a removable mounting plate removable faceplate 37 that removably attaches onto the front face of the integrated unit 6—e.g. by friction-fit push clips or similar, sufficient to hold the faceplate 37 in place in use or during transport, but allowing the faceplate 37 to be removed e.g. by pressing a knife blade under one side and twisting or similar. The faceplate 37 includes an aperture that aligns with the control screen 9, so that the screen can be viewed through the aperture in use. FIG. 14 shows a schematic cross-section of the front surface of the integrated unit 6, viewed from above. For clarity, the various elements shown in FIG. 8 are shown not in contact with one another. As shown in FIG. 14, the face plate 37 includes a concave hollow, depression or recess 38, into which the knob 8 locates in use. The depression 38 is sized and shaped so that the knob 8 fits snugly. The bottom of the depression 38 contains a fastening mechanism 39. In the preferred embodiment, the fastening mechanism 39 is formed as an integral part of the plate 37. In the preferred embodiment, the fastening mechanism 39 is a ring or crown of sprung fasteners or fastening clips 39, with their tips or upper portions 60 facing or pointing inwards. The fastening clips 39 are aligned perpendicular to the base of the depression 38. The knob 8 is made up of a central, non-rotating portion or button 61 and an outer, rotatable portion or boss 62 that can be rotated either clockwise or anticlockwise by a user. The outer portion 62 is ring-shaped, with a central aperture. The inner portion 61 has a T-shape in cross-section, with fasteners 63 integral with the upright of the T. In use, the fasteners 63 connect with the sprung fasteners 39 to hold the inner portion in position. The knob assembly is assembled by placing the outer (rotatable) portion 62 of the knob 8 in position in the depression 38, and then pushing the inner (non-rotatable) portion 61 into position. The flat upper part of the inner portion acts as a flange to hold the outer portion 62 in position. In the preferred embodiment, the outer portion 62 also has a slight central hollow, with the cross-portion of the T-section of the inner portion 62 fitting snugly into this hollow so that the inner portion 61 and the outer portion 62 together form a flush outer surface.

What has been described above is the preferred form of fastening mechanism to hold the knob 8 in position on the faceplate 37. However, any suitable fastening mechanism could be substituted for the one described.

The knob 8, or more specifically the outer portion 62, is fitted with a ring magnet 45. The outer portion 62 generally has the form of a hollow cup, with the open face facing inwards towards the centre of the depression 38 in use. The ring magnet 45 is fitted running around the inside of the outer portion, just below the rim. The centre of the ring magnet 45 is aligned with the axis of rotation of the knob 8. As the outer portion 62 rotates, the ring magnet 45 also rotates. The front face or wall 50 of the assisted breathing or integrated unit 6 is located behind the faceplate 37. The front face 50 includes an aperture 43, through which the rearmost part of the depression or recess 38 passes in use. A connector board 44 is located just behind, and generally planar with, both the faceplate 37 and the front face 50 of the integrated unit 6. Magnetic or magnetized sections 46 are embedded on the inner surface of the connector board 44. These are positioned so as to form a generally circular shape, corresponding to the ring magnet 45, so that the magnetized sections 46 align with the ring magnet 45. The magnetic fields of the ring magnet 45 and the magnetized sections 46 (detector magnetic components, or boss detector magnetic components) interact as the knob is rotated in use. Control circuitry and sensors (not shown) located within the blower unit 6 are connected to the ring magnet 45 so that as the boss portion 62 of the knob 8 is turned it can detect the fluctuations of the interacting magnetic fields. In the preferred form, the ring magnet 45 is continuous (that is, a continuous annular component), but divided into a number of discrete magnetic sections (That is, there are no physical gaps between the sections). The number of sections can be varied depending on the number of positions required. One advantage of using a ring magnet such as ring magnet 45 is that is has discrete sections. This means that as the boss portion of the knob 8 is rotated, it will have a number of discrete positions, having preferred ‘rest’ positions as the fields of the magnetized sections 46 and the fields of the sections of the ring magnet 45 interact to reach an equilibrium point, an effect known as ‘cogging’. The outer portion 62 of the knob 8 will rest at these equilibrium points until acted on by an external force—e.g. a user exerting a rotational force on the rotatable outer portion 62 of knob 8. The knob 8 will therefore tend to naturally ‘jump’ from one rest position to the next as it is rotated. As the relative positions of the magnets 45 and 46 changes, the fluctuations of the relative magnetic fields changes is detected by the sensors, and the results of the fluctuations are passed to the control circuitry 300 located inside the housing of the respirator 7 (e.g. located on the circuit board 44), which alters the output parameters of the integrated unit 6 according to pre-programmed responses (e.g. altering the power to the heater base 23, fan speed, etc) as required by a user.

The preferred form of ring magnet 45 and magnetized sections 46 has been described above. It should be noted that the positions of the ring magnet 45 and magnetized sections 46 could be reversed. Also, the ring magnet 45 could be composed of discrete sections, with gaps between them. That is, an annular arrangement of individual magnetic components. Magnetized sections 46 have been described. These could be actual magnets, or alternatively these could be electromagnetic elements that act as both magnets and sensors to exert a cogging force and provide positioning feedback.

In the preferred embodiment, the knob 8 is also adapted to allow limited movement along its axis of rotation 51. That is, it can be pressed inwards to act as a button. This can be achieved in a number of ways. However, in the preferred embodiment, a spring (not shown) is placed inside the circle or crown of the preferred form of fastening mechanism 39. When compressed, this spring is slightly under compression, and pushes outwards against the knob 8 so that it has a rest position when not depressed and an operative position when depressed. When pressed inwards towards the integrated unit 6, the spring is compressed slightly more, and will act to return the knob 8 to its initial position once the pressing force is removed. The centre of the knob 8 also holds a magnet 48. A corresponding central magnet 49 (or button detector magnetic component) is located at the centre of the circle formed by sections 46. In a similar fashion to that described above, as the relative positions of the magnets 48 and 49 changes, the fluctuations of the relative magnetic fields are detected, and these changes are passed to a control unit that varies the output parameters of the integrated unit 6 accordingly. For example, using the arrangement described above, the knob 8 can be rotated clockwise and anticlockwise to scroll between menu options, and then pressed inwards to choose the option to which the user has scrolled. The knob 8 can also be used as e.g. an on/off switch, either by scrolling to the required on/off menu choice and pressing, or by pressing and holding the knob in for a longer period than would naturally occur if the unit 6 was accidentally knocked—for example 5 seconds. Alternatively, the controls could be set so that a user is required to pull the knob 8 slightly out from the unit 6 to turn it off.

What has been described above is an assembly where the medical device (blower unit 7) includes a faceplate 37 which includes a recess, and which fits over the front face 50 of the blower 7. The faceplate is unbroken, in that there are no apertures or gaps through which moisture or dirt can enter the medical device. Also, the components external to the blower 7 are not moisture or dirt sensitive, so if they get wet or dirty, their operational effectiveness is not adversely affected. It should be noted that what is described above is the preferred embodiment, and the principles of the operation could be applied equally well to a device which does not include a separate faceplate, and which has a single flat face (i.e. no recess), with magnetic elements 46, 63 located behind the face, and the control knob, boss, fastening mechanism, etc located external to the face. It should also be noted that another possible variation of the layout described above could also be used, with the front face 50 unbroken and including a recess, and the faceplate including an aperture through which the control knob locates into the recess on the faceplate. It should also be noted that the faceplate does not have to be present at all, but is present in the preferred forms.

Control Menu

The preferred form of display shown on the display panel 9 is shown in FIG. 15. In the preferred embodiment, the control menu as displayed on the display 9 is a single layer menu, in order to keep the operation of the unit 6 simple. In the preferred embodiment, the display is an LCD display, with a circular ring of options around the outside of the display. The display also can include various indicators (e.g., a smiley face shaped indicator to indicate compliance or progress toward compliance). At a central portion of the illustrated display 9 is a clock read out (see the inclusion of “am/pm” below the number readout indicators). In some embodiments, the clock can be adjusted to account for travel to differing time zones. Such an adjustment can be performed in any suitable manner and can allow for data logging of compliance data that allows changes in time zones to be reflected in the data.

In addition, the display indicates a music note just below the numbers and an alarm bell just to the right of the music note. The music note relates to the ability of the apparatus to play music files and other sound files. In some embodiments, the sound, audio or music file can be contained on a media stick, a solid state memory component, a flash drive or the like. More preferably, the files are contained on a removable memory component. Thus, the display can facilitate the playback of sound, audio, music files or the like. The alarm bell relates to the ability of the apparatus to function as an alarm clock. Thus, it is possible to awaken to music, to fall asleep to music or to be awakened by other sounds. See PCT/NZ2009/000151, filed on Jul. 29, 2010, which is hereby incorporated by reference in its entirety. These features improve the user-friendly nature of the device and provide a better experience for the user when compared with previously marketed breathing assistance devices.

As the knob 8 is rotated, each of the options will light up in turn. When the knob is depressed, that option will be chosen. Once an option is chosen, for example ‘Output power’, the level of this parameter can be adjusted by rotating the knob 8 clockwise and anticlockwise. A user can then exit this submenu and return to the main menu by, for example, tapping the knob inwards or pulling it outwards. The control circuitry can be programmed as required. Other options can be pre-programmed as required. For example, pushing and holding in the knob 8 (or pulling it outwards and holding it out) could turn the unit off. It is preferred that the discrete positions (the ‘cogging’ positions) that the knob 8 reaches as it is rotated correspond to different menu options.

Blower Unit

The internal structure of the blower unit 7 will now be described with reference to FIGS. 5 and 7-11. In the preferred embodiment, heater base 23 is located at the bottom of the compartment 11, as described above. It should be noted that the blower unit and humidification chamber could be configured so that the volume of water within the humidifier chamber is heated e.g. through the side walls. That is, contact with a heater element or unit through a heat conducting surface on the side wall of the chamber, rather than on the base of the chamber. This configuration would achieve substantially the same effect. However, heating through the base is preferred for reasons of simplifying the chamber construction and overall operation of the heater/humidifier unit. When ‘heater base’ is referred to in this specification, it should be taken to mean heating through the base of the humidifier chamber, or alternatively the side walls.

As described above, the integrated unit 6 includes an inlet vent 101 to draw air in from atmosphere. The integrated unit 6 also includes a mechanism and structure by which a pressurized air flow is provided from the inlet vent 101 to the humidifier chamber. The vent 101 can be located wherever is convenient on the external surface of the integrated unit 6, but in the preferred embodiment, as shown in FIGS. 7 and 8, it is located on the rear face of the blower unit 7, on the right hand side of the rear face (right hand side when looking forwards). In the preferred embodiment, air is drawn in through the vent 101 by a fan unit 100 that provides a pressurized gases stream through the blower unit 7. The pressurized gases stream is ducted or otherwise directed from the inlet vent 101 through the casing to the humidifier inlet port 13. The air path and the ducting will be described in detail in the ‘Fan Unit and Air Path’ section below. In use, air exits the main body of the blower unit 7 via the inlet port 13 and enters the humidifier chamber 12, where it is humidified and heated, before passing out of the chamber 12 through the outlet port 14, which is directly connected to the patient outlet 25. The heated humidified gas is then passed to the user 3 via e.g. a conduit 21. The patient outlet 25 is adapted to enable pneumatic attachment of the patient conduit 21, and in the preferred embodiment, electrical connection at the outlet 25 is also enabled via an electrical connector 19.

As shown in FIGS. 4 and 6, the inlet port 13 is offset. That is, the port is positioned facing into or out of the corner of the integrated unit 6 between the side wall and the front face. In contrast, outlet port 14 is directly aligned with the rear wall of the integrated unit 6. It can also be seen that the circular compartment 11 is sized to just fit within the generally square plan view profile of the integrated unit 6. Offsetting the inlet port 13 towards the corner allows a more efficient use of the space within the assisted breathing integrated unit 6, and allows the size of the integrated blower/humidifier unit 6 to be minimized.

Fan Unit The fan unit and ducting of the preferred embodiment will now be described with reference to FIGS. 5, 7-12 and 16. The fan unit 100 is intended to sit in the recess 400 shown in FIG. 5 b. Air is drawn into the fan unit 100 through an inlet vent 101. Once inside the housing, the air is then is drawn upwards into the casing of the fan unit 100 through an aperture 110 in the centre of the casing of the fan unit 100, and is directed outwards through a duct 120 (shown schematically as hidden detail in FIG. 16) to the inlet 13. The duct 120 runs from the recess 400 up between the side wall and the front wall of the integrated unit 6. The air path through the fan unit is shown by arrows 130. In the preferred embodiment, fan unit 100 is electromagnetically powered, with magnetic segments 111 interacting with electromagnetic coils 112, located above the fan unit 100, as shown in FIG. 7. The fan 110 is held in place by a bearing unit 113 that includes a spindle for the fan 110.

Fan Unit and Air Path

The fan unit and ducting of the preferred embodiment will now be described with particular reference to FIGS. 8 to 12. A power supply sub-housing 500 is located within and integrated with the outer housing or outer shell of the breathing unit 7. The power supply sub-housing 500 is a rectangular cuboid structure at the rear of the blower unit 7, integrated as part of the rear wall 80 of the blower unit 7. The cuboid sub-housing 500 shares one of its two largest faces with the rear wall 80 of the blower unit 7 (although it should be noted that the outer dimensions of the sub-housing 500 are substantially less than the dimensions of the rear wall 80). The other large face 510 is common with the fan recess 400, and the humidifier aperture 1000. The sub-housing 500 is generally centrally located on the inner rear wall of the blower unit 7. Once the unit is assembled, the sub-housing 500 is substantially closed off from atmosphere and the rest of the internal volume of the outer shell of the blower unit 7, apart from small apertures necessary for external electrical connections or similar (not shown). The power supply component board 501 is comprised of electrical components connected to a mother board, and slotted into the space within the sub-housing 500 during assembly. It is not necessary to detail or individually number all of the components used to make up the power supply component board 501, as the make-up and variations of the construction of power supply boards is well-known in the art. However, it should be noted that these components generate heat during use, which cannot dissipate or vent to atmosphere due to the power supply being enclosed. This heat therefore builds up, potentially leading to less efficient operation. It is preferred that the sub-housing 500 is sealed or enclosed in the sub-housing 500 in this manner in order to protect the components of the power supply component board 501, so that dirt, moisture or similar cannot enter the sub-housing 500. However, the power supply component board could be merely located within the external casing or shell of the blower unit 7. It should be noted that when ‘power supply’ or ‘power supply unit’ are referred to in this specification, this means either the power supply sub-housing 500, the power supply component board 501, or both together. In some embodiments, a power cord that is adapted to be plugged directly into a power supply outlet (e.g., house power) can extend outward from the housing through one of the front wall, the side walls or the rear wall.

In order to help reduce the temperature of the sub-housing 500 and the temperature of the components of the power supply component board 501 in the sub-housing 500, air from atmosphere is drawn into the housing by the fan unit 100 and then ducted directly over the power supply unit sub-housing 500 to cool the power supply component board 501. It is preferred that the air is ducted over the sub-housing 500 directly after it enters the outer housing of the integrated unit 6, as the air will be at its coolest at this point—direct from the atmosphere. In order to most effectively cool the power supply component board 501 and the sub-housing 500, the air is ducted over the greatest possible surface area of the sub-housing 500, while still maintaining the integrity and operation of the integrated unit 6, and still maintaining a practical compact and integrated design.

Air from atmosphere is drawn in through the air inlet vent 101, the side of which is substantially the same height as one of the side walls of the sub-housing 500. In the preferred embodiment, the inlet 101 is directly next to the sub-housing 500. It should also be noted that in the preferred form, the height of the air inlet 101 is substantially the same as the dimension of the neighboring wall 502. The air entering the external shell through the inlet 101 therefore immediately contacts the side wall 502 of the sub-housing 500. This first contact is made across substantially the entire surface area of the wall, as the height dimension of the neighboring vent 101 is substantially the same as the height or length of the wall 502. This has the advantage that all the air contacting this wall will be at atmospheric temperature as it contacts the wall. The air is then drawn by the fan 100 upwards and across the top wall 503 of the sub-housing 500, passing across or over the entire outer surface area of the top wall 503. The air is then ducted down the other or inner side wall 504 of the sub-housing 500, passing across the entire outer surface area of wall 504. It should be noted that the walls of the sub-housing 500 are as thin as is practical in order to minimize their insulating effect, and maximize heat transfer between the air flow and the power supply board. The air is then drawn inwards, away from the power supply, along the curved path 505, through aperture 506 into the recess 400 and then into the fan unit 100. Air is drawn into the fan unit 100 through aperture 110, and is then directed outwards through a plenum chamber or duct 120 inside the blower 7 to the inlet 13 (duct 120 is shown schematically and for the purposes of illustration only as hidden detail in FIG. 16. The representation of the duct 120 as shown in FIG. 16 does not necessarily match the actual path or size of the duct). The duct 120 runs from the recess 400 up between the right side wall (from behind looking forwards) and the front wall of the integrated unit 6, up to the blower inlet port 13.

It can be seen that for an outer casing with a sub-housing 500 and air path configured in this manner, air passes over the entire surface area of three walls (502, 503, and 504) of the sub-housing 500, substantially adding to the cooling of the power supply component board 501. This is the most preferred configuration of the cooling path, as manufacture in this configuration allows repeatability and a high number of units within design tolerance, while minimizing costs. It has been found that this configuration gives the most efficient use of both space and air cooling, allowing a good degree of cooling, while still ensuring the unit 6 can be configured compactly to minimize footprint. It should be noted that if the power supply component board 501 is not enclosed in a sub-housing, the cooling air can be ducted directed over the board and the components thereon. Other configurations are possible. For example, the air could be ducted along a space between the large wall 510 of the sub-housing 500, and the rear wall of the humidifier aperture 1000. However, in order to make this configuration work effectively, without the air in this space stagnating, the gap between the fan recess 400 and the power supply sub-housing 500 has to be over a certain size, and this can detract from the overall compact nature of the overall structure. Furthermore, it can add to the manufacturing difficulty. It should also be noted that the blower unit could be redesigned to allow the air path to pass over the lower wall of the sub-housing, as well as or instead of, the side and upper walls.

As described above, the sub-housing 500 is located at the rear of the blower unit 7. It could of course be located anywhere suitable, such as the sides or base, with the air ducting and inlet configured and located accordingly. The rear is preferred as this configuration allows the other elements of the blower unit to be configured to minimize the overall device ‘footprint’.

In the most preferred form, the outer surfaces of the walls 502, 503 and 504 are ribbed, in order to increase the surface area available for cooling and to aid in heat dissipation by acting in a similar manner to heat sinks. Also, in the most preferred form, air flows over at least two and preferably three walls of the sub-housing 500 in order to maximize the cooling.

Carry Case

As has been noted above, one problem that can occur when a user packs their breathing assistance apparatus in a case for travel is forgetting to empty the humidifier chamber, and the contents may then spill during travel, causing at least inconvenience. It is a long felt want by users of domestic breathing assistance apparatus that this problem is addressed.

In the preferred embodiment, a carry case 600 is used with the integrated unit 6 described above to help overcome this problem. When a user wishes to pack their breathing assistance device for transport, the carry case 600 can be used.

The carry case 600 is shown in FIGS. 18-20. The carry case 600 is formed from a rigid plastic in the preferred embodiment. The case 600 in the preferred form comes in two parts or halves, an upper half 604 and a lower half 605 (half is used in this context as a term of convenience and does not necessarily indicate that the upper and lower halves are required to be exactly or even close to the same size). In the closed position, the carry case 600 has one generally flat end 601, with the opposite end 602 coming to a rounded point when viewed side on. It is preferred that end 602 includes a handle 609 to aid a user in transporting the case 600. In the preferred form, the handle 609 is formed when the case is closed, the upper and lower halves 604, 605 including apertures that align to form one aperture when the case is closed, a user gripping the handle portion thus formed. The parts that form the handle are preferably rounded, and sized to facilitate their acting as a handle. The case 600 can be stood upright and rested on the flat end, or end base 601, in use. Alternatively, the carry case can be rested on the side base 603 which forms the lower side of the lower half 605. It should be noted that ‘upper’ and ‘lower’ are only directional indicators when the carry case 600 is resting on the side base 603. The two halves are connected by hinges—the upper half 604 attached to the lower half 605 so that the case can be opened by e.g. rotating or pivoting the upper half 605 relative to the stationary lower half 605, with the case 600 resting on side base 603, for packing or unpacking. In the fully closed position, the edges of the two come together to enclose a volume of space or an internal volume of the case. The hinges are adapted to allow the two halves a full range of movement—e.g. substantially 180 degrees of rotation relative to one another. This allows the upper half 604 to be rotated far enough that its outer surface can rest on the same surface as the lower half 605, for example a table or similar, and a user can freely access the inside of the case. In the preferred embodiment, the hinges 610 are located at the flat end 601, and form part of the flat base in use. The inside contains packaging or padding 606, in the preferred form including a pocket or recess 608 formed by moulding and shaping the padding 606, so that the pocket 608 conforms generally to the external shape and dimensions of the blower unit 7, so that at least the lower portion of the blower unit can be placed in the recess 608 in the packaging 606 in an upright position, with the packaging or padding 606 partially enclosing at least the lower portion of the blower unit 7, to hold the blower unit 7 securely in position during transport. As described above, the preferred form of chamber 31 is a top fill chamber with a removable lid 32. To prevent the user from inadvertently packing their integrated unit 6 away with chamber 31 still partially full and containing liquid, the carry case 600 is adapted in the following manner so that the case 600 cannot be closed fully if the lid 32 is still in position on the chamber 31. It should be noted at different forms of the carry case could be used to transport other types of systems that provide heated, humidified gases to a user. For example, systems that have push fit chambers filled through their inlets or outlets, rather than through a top fill aperture.

When the user needs to transport their integrated blower/humidifier unit, the user packs the integrated unit 6 in the carry case 600 by placing the integrated unit 6 in recess 608 in the packaging 606, the recess 608 shaped to enclose at least the base of the integrated unit 6. It is intended that the case 600 is as compact as possible. This helps a user to transport their unit as, for example, hand luggage on an aircraft, as it can be fitted in an overhead locker. Therefore, in the preferred form, the humidifier chamber 31 is located in the same position in which it is used in the blower 7, and not in a separate recess. The upper half 604 of the case 600 includes at least one protrusion 607 extending inwards from the inner surface of the upper half 604 (i.e. downwards towards lower half 605). The at least one protrusion 607 is sized and shaped so that the upper half and lower half 604, 605 cannot be brought fully together (i.e. the case 600 cannot be closed) when the humidifier chamber lid 32 is still in position on the chamber 31. When the humidifier chamber lid 31 is removed, the protrusion or protrusions 607 fit down inside the chamber 31. The lid 32 therefore has to be removed from the chamber 31 before the carry case 600 can be shut. It is preferred that the separate handle 22 can be located onto the blower unit 7, with the protrusion or protrusions 607 extending past the handle 22 to extend downwards into the chamber 31. The carry case 600 is preferably adapted to include an internal pocket or similar—e.g. in the packaging 606—which the user can use to store the lid 32 for travel.

It is preferred that the carry case can also be fitted with a strap or straps, to allow it to be carried in the same manner that a day sack or small knapsack would be carried, or slung over one shoulder and carried by one strap.

It should be noted that blower unit 7 is used as an example for the above described preferred form of carry case. In other, alternative forms, the carry case is adapted to carry respiratory humidification systems of the type where the humidifier chamber and the blower unit rigidly mate. In this alternative form, the padding includes a first pocket and a second pocket. The first pocket is adapted to enclose at least the base of the blower unit, and the second pocket is adapted to at least partly enclose the humidifier chamber. The two pockets are separate, so that the humidifier chamber will be disconnected from the blower before the chamber and the blower can be placed in their respective pockets. That is, the blower and the chamber cannot be mated to be correctly stored in the case in their respective pockets. The inner surface of the upper half includes a protrusion, facing inwards. When the case is closed, the protrusion locates into a space adjacent to the blower pocket, and increases the likelihood that the blower cannot be placed into the first pocket with the chamber rigidly mated to the blower, and the lid them closed. The protrusion will interfere with the chamber if a user attempts to close the lid while the chamber is in position on the blower.

To provide for increased compliance, the device described above has been designed with a number of features. For example, the user-friendliness of the device may be important in improving compliance. For this reason, the display has been positioned on the front face of the unit, which improves user-friendliness. In addition, the display has been designed to incorporate a clock. Moreover, in some configurations, the clock is designed to accommodate changes in time zones for travelers. The display also has been designed to provide compliance feedback to the user, such as through a smiley face shaped indicator. The device also has been designed with a control knob interface that is easy to use and provides a user-friendly experience in controlling the device. To improve usability, the knob is positioned adjacent to the display.

Similarly, a device that is aesthetically pleasing has been found to promote interaction and reduce cognitive dissonance as a barrier to therapy. Thus, the illustrated device has been designed to incorporate into a single small footprint housing several components that previously were provided as separate components. For example, the illustrated device integrates into a single housing the blower unit, the humidifier unit and the power supply. In so doing, the illustrated device resembles a larger alarm clock and blends more aesthetically with the environment of a bedroom. In fact, the illustrated device includes the abilities to play music or sound files and to set alarms, which emulates features normally found on alarm clocks, such that the device can replace an alarm clock in a bedroom setting. Moreover, the smaller footprint allows the illustrated device to fit comfortably in its entirety on a bedside stand. Furthermore, the illustrated device has been designed with few, if any, sharp corners such that the device takes on a sleek appearance.

Through the incorporation of one or more of the above-described features, the illustrated device has been found to elicit positive emotional and cognitive responses from patients. As a result, OSA patients have been found to use the illustrated device more than devices with a different aesthetic and user interface. The above-described features result in the positive user response and this translates into increased compliance. A discussion of an online survey and compliance study are found below.

Over a period of time, OSA patients were invited to take part in an online survey. A total of 179 people completed the survey, of which 169 (94%) said they were diagnosed with OSA. Of the 158 people who said they used a CPAP device, 55 (35%) used a ResMed device, 52 (33%) used a Fisher & Paykel Healthcare device, and 38 (24%) used a Respironics device. When first diagnosed with OSA, the majority of respondents (52%) had a negative initial reaction (‘freaked out’, ‘confused and overwhelmed’) to having to use a CPAP device while 44% had a positive responses (‘excitement’, ‘finally, some relief!’). In contrast, 48% of respondents reported positive initial reactions to the ICON™ and only 19% reported negative reactions. When shown a picture of the illustrated device, 59% of those who had not seen it before reported positive responses while only 4% had a negative initial response to the product. This is clear evidence of the positive psychological impact of the illustrated device.

Positive comments on the illustrated device included: ‘Nice machine, easy to use’, ‘ . . . better design . . . ’, ‘ . . . stylish looking machine’, ‘looks good’, and ‘it's small and compact . . . ’ These comments are strongly related to the emotional (aesthetic) and cognitive (ease of use) elements. Specific features that were identified as more likely to promote CPAP usage included ease of use, user-friendly interface, small and compact size, small number of connecting parts, internal power supply, discreet, rounded with smooth edges, and sleek looking. After seeing the features and a picture of the illustrated device, almost half (87, 49%) of respondents said they would be more likely to use the illustrated device than their current CPAP device.

Current CPAP users who had a Fisher & Paykel Healthcare device were asked to try the illustrated device with the same settings as their previous device. After one week, compliance with the illustrated device was compared to the compliance with the previous device. A total of 18 patients completed the study. On the days when CPAP was used, the compliance with the illustrated device was, on average, higher than the previous device. When compliance is calculated including days when the CPAP was not used, the illustrated device was used for about 66 minutes more than the previous device.

All technological settings were kept the same as the previous device in this study so the only difference was the style and function of the illustrated device. It is possible that some of the increase in due to the Hawthorne effect (simply by being in a study, the behavior of participants is altered). However, the increase in compliance is rather large to be only due to this. The only known comparable study was recently completed by ResMed where patients were given a new S9 device and it was shown that they used it for, on average, 30 minutes more per night. This is under half what was shown by the Fisher & Paykel study.

Improved perception of treatment and more positive emotional and cognitive states result in increased adherence to therapy. As discussed above, the illustrated device elicits more positive emotional and cognitive responses from OSA patients due to the style and features in the design of the device. This has also translated into over 1 hour longer compliance with the illustrated device as compared to equivalent therapy on an older device.

Although the present invention has been described in terms of a certain embodiment, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow. 

What is claimed is:
 1. A positive airway pressure device configured to improve patient compliance by providing an improved user-friendliness and by reducing cognitive dissonance as a barrier to therapy, the positive airway pressure device comprising a housing having a substantially square profile and a volume less than 0.008 m³, the housing comprising an outer surface, the outer surface comprising a front wall, a rear wall, a first side wall extending between the front wall and the rear wall and a second side wall extending between the front wall and the rear wall; a control knob and a control display positioned on the front wall, the control display being positioned directly above the control knob, the control display comprising a clock display; a humidification compartment having a substantially round profile disposed within the housing, an upper portion of the humidification compartment being covered by a removable lid, the lid being removably attached to the housing and defining a handhold location for carrying of the positive airway pressure device, the humidification compartment being adapted to receive a humidifier chamber, the humidifier chamber being an open top container with a heat-conducting surface and fully enclosed within the humidification compartment except for the open top of the humidification chamber; an airflow outlet extending from one of the front wall, the first side wall, the second side wall and the rear wall, the airflow outlet being pivotable or rotatable relative to the housing, the airflow outlet being connected to one of the humidification chamber and one of the front wall, the first side wall, the second side wall and the rear wall; an internal power supply being substantially enclosed within a substantially rectangular cuboid sub-housing disposed in a rear portion within the housing, the sub-housing integrated as part of the rear wall of the housing and including a first sub-housing wall having a first surface area, a second sub-housing wall having a second surface area, and a third sub-housing wall having a third surface area, the internal power supply comprising a power supply component board configured to be connected to a mains voltage source with a power cord; and a fan unit disposed in a recess beneath the humidification compartment, an inlet to the fan unit being fluidly connected to ambient air and extending through at least one of the front wall, the first side wall, the second side wall, and the rear wall, the fan unit configured to cause air from atmosphere to pass over the first surface area of the first sub-housing wall, the second surface area of the second sub-housing wall, and the third surface area of the third sub-housing wall.
 2. The positive airway pressure device of claim 1, wherein the clock display is time-zone adjustable.
 3. The positive airway pressure device of claim 1, wherein the humidifier chamber is dishwashable.
 4. The positive airway pressure device of claim 1, wherein the humidifier chamber is adapted to hold at least 420 ml of water.
 5. A positive airway pressure device configured to improve patient compliance by providing an improved user-friendliness and by reducing cognitive dissonance as a barrier to therapy, the positive airway pressure device comprising a substantially square-shaped housing comprising an outer surface, the outer surface comprising a front surface; a control knob and a control display positioned on the front surface, the control display comprising a clock display; a blower unit, a substantially round-shaped humidification compartment and an internal power supply all disposed within the housing, the internal power supply comprising a power supply component board configured to be connected to a mains voltage source with a power cord, the power supply being substantially enclosed in a sub-housing within the housing, the sub-housing being cuboid and integrated as part of a rear wall of the housing, the sub-housing including a first sub-housing wall having a first surface area, a second sub-housing wall having a second surface area, and a third sub-housing wall having a third surface area, the blower unit disposed in a recess beneath the humidification compartment, the blower unit configured to cause air from atmosphere to pass over the first surface area of the first sub-housing wall, the second surface area of the second sub-housing wall, and the third surface area of the third sub-housing wall; and wherein any horizontal cross-sectional area of the housing does not exceed 40,000 mm² whereby the housing that contains the blower unit, the humidification compartment and the internal power supply occupies less than 20% of a top of a bedside stand having a width of 480 mm and a depth of 480 mm, the housing having a volume of less than 0.008 m³.
 6. The positive airway pressure device of claim 5, wherein the humidification compartment is adapted to receive a humidifier chamber, the humidifier chamber being adapted to hold at least 420 ml of water.
 7. The positive airway pressure device of claim 5, wherein an upper portion of the humidification compartment is covered by a removable lid, the lid being removably attached to the housing.
 8. The positive airway pressure device of claim 7, wherein the removable lid defines a handhold location for carrying of the positive airway pressure device.
 9. The positive airway pressure device of claim 5, wherein the housing further comprises a first side surface and a second side surface each extending rearward from the front surface, a smooth contour being formed by the front surface, the first side surface and the second side surface.
 10. The positive airway pressure device of claim 9, wherein an inlet to the blower unit is fluidly connected to ambient air and extends through at least one of the front surface, the first side surface, the second side surface and a rear surface.
 11. The positive airway pressure device of claim 10 further comprising an airflow outlet extending from one of the front surface, the first side surface, the second side surface and the rear surface, the airflow outlet being pivotable or rotatable relative to the housing, the airflow outlet being connected to one of the humidification chamber and one of the front surface, the first side surface, the second side surface and the rear surface.
 12. The positive airway pressure device of claim 5, wherein the display comprises a smiley face shaped indicator.
 13. The positive airway pressure device of claim 5, wherein the control display facilitates playing of sound or music files from a removable memory source.
 14. The positive airway pressure device of claim 5, wherein the clock display is time-zone adjustable.
 15. The positive airway pressure device of claim 5, wherein the humidification compartment receives a removable humidifier chamber and the removable humidifier chamber is dishwashable. 